364 research outputs found

    A Computational Method for the Rate Estimation of Evolutionary Transpositions

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    Genome rearrangements are evolutionary events that shuffle genomic architectures. Most frequent genome rearrangements are reversals, translocations, fusions, and fissions. While there are some more complex genome rearrangements such as transpositions, they are rarely observed and believed to constitute only a small fraction of genome rearrangements happening in the course of evolution. The analysis of transpositions is further obfuscated by intractability of the underlying computational problems. We propose a computational method for estimating the rate of transpositions in evolutionary scenarios between genomes. We applied our method to a set of mammalian genomes and estimated the transpositions rate in mammalian evolution to be around 0.26.Comment: Proceedings of the 3rd International Work-Conference on Bioinformatics and Biomedical Engineering (IWBBIO), 2015. (to appear

    Application of predicate logic for failure detection in SCADA systems

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    We consider the task of failure detection and localization. It is based on the analysis of the information flow state change in the system. We suggest a structural and logical model to describe SCADA of any topology. It is possible to form diagnostic features of independent failure detection. They are based on the characteristic functions of three-valued logic. We determine the predicate system of knowledge representation to implement the method of SCADA diagnostics in the event of incomplete data.Розглядається задача виявлення та локалізації відмов у SCADA на основі аналізу зміни стану інформаційних потоків у системі. Пропонується структурно-логічна модель опису SCADA будь-якої топології. На основі характеристичних функцій тризначної логіки формуються діагностичні ознаки виявлення незалежної відмови. Визначається предикатна система подання знань для реалізації методу діагностики працездатності SCADA в умовах неповних даних / недостовірних даних

    Information system for analysis and forecasting of futures markets

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    We considered different approaches to the analysis and forecasting techniquesof futures markets.We also studied methods of working with the use of technical analysis. Existing software products that allow technical analysis of futures markets are considered. All of them realize powerful indicator and oscillator analysis, they are equipped with fast access to mass media, but they limit this. Other existing methods of technical analysis are not used in them

    Metrological characterization of the pulsed Rb clock with optical detection

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    We report on the implementation and the metrological characterization of a vapor-cell Rb frequency standard working in pulsed regime. The three main parts that compose the clock, physics package, optics and electronics, are described in detail in the paper. The prototype is designed and optimized to detect the clock transition in the optical domain. Specifically, the reference atomic transition, excited with a Ramsey scheme, is detected by observing the interference pattern on a laser absorption signal. \ The metrological analysis includes the observation and characterization of the clock signal and the measurement of frequency stability and drift. In terms of Allan deviation, the measured frequency stability results as low as 1.7×1013 τ1/21.7\times 10^{-13} \ \tau^{-1/2}, τ\tau being the averaging time, and reaches the value of few units of 101510^{-15} for τ=104\tau=10^{4} s, an unprecedent achievement for a vapor cell clock. We discuss in the paper the physical effects leading to this result with particular care to laser and microwave noises transferred to the clock signal. The frequency drift, probably related to the temperature, stays below 101410^{-14} per day, and no evidence of flicker floor is observed. \ We also mention some possible improvements that in principle would lead to a clock stability below the 101310^{-13} level at 1 s and to a drift of few units of 101510^{-15} per day

    Information system for analysis and forecasting of futures markets

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    We considered different approaches to the analysis and forecasting techniquesof futures markets.We also studied methods of working with the use of technical analysis. Existing software products that allow technical analysis of futures markets are considered. All of them realize powerful indicator and oscillator analysis, they are equipped with fast access to mass media, but they limit this. Other existing methods of technical analysis are not used in them

    Limited Lifespan of Fragile Regions in Mammalian Evolution

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    An important question in genome evolution is whether there exist fragile regions (rearrangement hotspots) where chromosomal rearrangements are happening over and over again. Although nearly all recent studies supported the existence of fragile regions in mammalian genomes, the most comprehensive phylogenomic study of mammals (Ma et al. (2006) Genome Research 16, 1557-1565) raised some doubts about their existence. We demonstrate that fragile regions are subject to a "birth and death" process, implying that fragility has limited evolutionary lifespan. This finding implies that fragile regions migrate to different locations in different mammals, explaining why there exist only a few chromosomal breakpoints shared between different lineages. The birth and death of fragile regions phenomenon reinforces the hypothesis that rearrangements are promoted by matching segmental duplications and suggests putative locations of the currently active fragile regions in the human genome

    ETEKOS experimental ecological system

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    The problem of changes in the ecology resulting, for example, in increases in water temperature because of discharges from large thermal power plants is considered. An experiment creating a model of such an ecological system is described

    Towards the electron EDM search. Theoretical study of PbF

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    We report ab initio relativistic correlation calculations of potential curves and spectroscopic constants for four lowest-lying electronic states of the lead monofluoride. We also calculated parameters of the spin-rotational Hamiltonian for the ground and the first excited states including P,T-odd and P-odd terms. In particular, we have obtained hyperfine constants of the 207^{207}Pb nucleus. For the 2Π1/2^2\Pi_{1/2} state A=6859.6A_\perp=-6859.6 MHz, A=9726.9A_\|=9726.9 MHz and for the A2Σ1/2+^2\Sigma^+_{1/2} A=1720.8A_\perp=1720.8 MHz, A=3073.3A_\|=3073.3 MHz. Our values of the ground state hyperfine constants are in good agreement with the previous theoretical studies. We discuss and explain seeming disagreement in the sign of the constant AA_\perp with the recent experimental data. The effective electric field on the electron EeffE_{eff}, which is important for the planned experiment to search for the electric dipole moment of the electron, is found to be 3.3 * 10^{10} V/cm

    Proton acceleration in analytic reconnecting current sheets

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    Particle acceleration provides an important signature for the magnetic collapse that accompanies a solar flare. Most particle acceleration studies, however, invoke magnetic and electric field models that are analytically convenient rather than solutions of the governing magnetohydrodynamic equations. In this paper a self-consistent magnetic reconnection solution is employed to investigate proton orbits, energy gains, and acceleration timescales for proton acceleration in solar flares. The magnetic field configuration is derived from the analytic reconnection solution of Craig and Henton. For the physically realistic case in which magnetic pressure of the current sheet is limited at small resistivities, the model contains a single free parameter that specifies the shear of the velocity field. It is shown that in the absence of losses, the field produces particle acceleration spectra characteristic of magnetic X-points. Specifically, the energy distribution approximates a power law ~ξ-3/2 nonrelativistically, but steepens slightly at the higher energies. Using realistic values of the “effective” resistivity, we obtain energies and acceleration times that fall within the range of observational data for proton acceleration in the solar corona
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